SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97712287f4a587afe40d4505162e38097c3585826fc475efecd153ad1fac7ad5' 
  AND token = '9+H10pFENQQJgQo+gHXqBETyncFR8omtdYkvAxwRsis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}